--[[
Ring Meters by londonali1010 (2009)
 
This script draws percentage meters as rings. It is fully customisable; all options are described in the script.
 
IMPORTANT: if you are using the 'cpu' function, it will cause a segmentation fault if it tries to draw a ring straight away. The if statement on line 145 uses a delay to make sure that this doesn't happen. It calculates the length of the delay by the number of updates since Conky started. Generally, a value of 5s is long enough, so if you update Conky every 1s, use update_num > 5 in that if statement (the default). If you only update Conky every 2s, you should change it to update_num > 3; conversely if you update Conky every 0.5s, you should use update_num > 10. ALSO, if you change your Conky, is it best to use "killall conky; conky" to update it, otherwise the update_num will not be reset and you will get an error.
 
To call this script in Conky, use the following (assuming that you save this script to ~/scripts/rings.lua):
    lua_load ~/scripts/rings-v1.2.1.lua
    lua_draw_hook_pre ring_stats
 
Changelog:
+ v1.2.1 -- Fixed minor bug that caused script to crash if conky_parse() returns a nil value (20.10.2009)
+ v1.2 -- Added option for the ending angle of the rings (07.10.2009)
+ v1.1 -- Added options for the starting angle of the rings, and added the "max" variable, to allow for variables that output a numerical value rather than a percentage (29.09.2009)
+ v1.0 -- Original release (28.09.2009)

    {
        -- Edit this table to customise your rings.
        -- You can create more rings simply by adding more elements to settings_table.
        -- "name" is the type of stat to display; you can choose from 'cpu', 'memperc', 'fs_used_perc', 'battery_used_perc'.
        name='time',
        -- "arg" is the argument to the stat type, e.g. if in Conky you would write ${cpu cpu0}, 'cpu0' would be the argument. If you would not use an argument in the Conky variable, use ''.
        arg='%I.%M',
        -- "max" is the maximum value of the ring. If the Conky variable outputs a percentage, use 100.
        max=12,
        -- "bg_colour" is the colour of the base ring.
        bg_colour=0x303030,
        -- "bg_alpha" is the alpha value of the base ring.
        bg_alpha=0.5,
        -- "fg_colour" is the colour of the indicator part of the ring.
        fg_colour=0x8F8F8F,
        -- "fg_alpha" is the alpha value of the indicator part of the ring.
        fg_alpha=0.5,
        -- "x" and "y" are the x and y coordinates of the centre of the ring, relative to the top left corner of the Conky window.
        x=191, y=145,
        -- "radius" is the radius of the ring.
        radius=32,
        -- "thickness" is the thickness of the ring, centred around the radius.
        thickness=4,
        -- "start_angle" is the starting angle of the ring, in degrees, clockwise from top. Value can be either positive or negative.
        start_angle=0,
        -- "end_angle" is the ending angle of the ring, in degrees, clockwise from top. Value can be either positive or negative, but must be larger (e.g. more clockwise) than start_angle.
        end_angle=360
    },
]]
settings_table = {    
    {
        name='cpu',
        arg='cpu0',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=291, y=61,
        radius=28.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='cpu',
        arg='cpu1',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=291, y=61,
        radius=22.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='memperc',
        arg='',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=371, y=61,
        radius=28.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='swapperc',
        arg='',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=371, y=61,
        radius=22.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='nvidia',
        arg='temp',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=451, y=61,
        radius=28.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='nvidia',
        arg='gpufreq',
        max=650,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=451, y=61,
        radius=22.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='downspeedf',
        arg='eth0',
        max=2500,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=611, y=61,
        radius=28.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='upspeedf',
        arg='eth0',
        max=145,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=611, y=61,
        radius=22.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='fs_used_perc',
        arg='/',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=691, y=61,
        radius=28.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='fs_used_perc',
        arg='/mnt/music',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=691, y=61,
        radius=22.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='if_match "${mpd_status}"=="Playing"}${mpd_percent}${else}${if_match "${mpd_status}"=="Paused"}${mpd_percent}${else}0${endif}${endif',
        --name='mpd_percent',
        arg='',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=771, y=61,
        radius=28.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
    {
        name='mpd_vol',
        arg='',
        max=100,
        bg_colour=0x303030,
        bg_alpha=0.5,
        fg_colour=0x8F8F8F,
        fg_alpha=0.5,
        x=771, y=61,
        radius=22.5,
        thickness=5,
        start_angle=-90,
        end_angle=270
    },
}
 
require 'cairo'
 
function rgb_to_r_g_b(colour,alpha)
    return ((colour / 0x10000) % 0x100) / 255., ((colour / 0x100) % 0x100) / 255., (colour % 0x100) / 255., alpha
end
 
function draw_ring(cr,t,pt)
    local w,h=conky_window.width,conky_window.height
 
    local xc,yc,ring_r,ring_w,sa,ea=pt['x'],pt['y'],pt['radius'],pt['thickness'],pt['start_angle'],pt['end_angle']
    local bgc, bga, fgc, fga=pt['bg_colour'], pt['bg_alpha'], pt['fg_colour'], pt['fg_alpha']
 
    local angle_0=sa*(2*math.pi/360)-math.pi/2
    local angle_f=ea*(2*math.pi/360)-math.pi/2
    local t_arc=t*(angle_f-angle_0)
 
    -- Draw background ring
 
    cairo_arc(cr,xc,yc,ring_r,angle_0,angle_f)
    cairo_set_source_rgba(cr,rgb_to_r_g_b(bgc,bga))
    cairo_set_line_width(cr,ring_w)
    cairo_stroke(cr)
 
    -- Draw indicator ring
 
    cairo_arc(cr,xc,yc,ring_r,angle_0,angle_0+t_arc)
    cairo_set_source_rgba(cr,rgb_to_r_g_b(fgc,fga))
    cairo_stroke(cr)        
end
 
function conky_ring_stats()
    local function setup_rings(cr,pt)
        local str=''
        local value=0
 
        str=string.format('${%s %s}',pt['name'],pt['arg'])
        str=conky_parse(str)
 
        value=tonumber(str)
        if value == nil then value = 0 end
        pct=value/pt['max']
 
        draw_ring(cr,pct,pt)
    end
 
    if conky_window==nil then return end
    local cs=cairo_xlib_surface_create(conky_window.display,conky_window.drawable,conky_window.visual, conky_window.width,conky_window.height)
 
    local cr=cairo_create(cs)    
 
    local updates=conky_parse('${updates}')
    update_num=tonumber(updates)
 
    if update_num>5 then
        for i in pairs(settings_table) do
            setup_rings(cr,settings_table[i])
        end
    end
end
